1. Polarization of 'water-skies' above arctic open waters: how polynyas in the ice-cover can be visually detected from a distance.
- Author
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Hegedüs R, Akesson S, and Horváth G
- Subjects
- Arctic Regions, Computer Simulation, Models, Statistical, Oceans and Seas, Reproducibility of Results, Sensitivity and Specificity, Algorithms, Environmental Monitoring methods, Ice Cover chemistry, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Information Storage and Retrieval methods, Refractometry methods
- Abstract
The foggy sky above a white ice-cover and a dark water surface (permanent polynya or temporary lead) is white and dark gray, phenomena called the 'ice-sky' and the 'water-sky,' respectively. Captains of icebreaker ships used to search for not-directly-visible open waters remotely on the basis of the water sky. Animals depending on open waters in the Arctic region may also detect not-directly-visible waters from a distance by means of the water sky. Since the polarization of ice-skies and water-skies has not, to our knowledge, been studied before, we measured the polarization patterns of water-skies above polynyas in the arctic ice-cover during the Beringia 2005 Swedish polar research expedition to the North Pole region. We show that there are statistically significant differences in the angle of polarization between the water-sky and the ice-sky. This polarization phenomenon could help biological and man-made sensors to detect open waters not directly visible from a distance. However, the threshold of polarization-based detection would be rather low, because the degree of linear polarization of light radiated by water-skies and ice-skies is not higher than 10%.
- Published
- 2007
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